Bumper stabilizer for can body side seamer



April 23, 1963 ED LAXO 3,086,487

BUMPER STABILIZER FOR CAN BODY SIDE SEAMER Filed Feb. 18, 1960 2 Sheets-Sheet 1 INVENTOR.

E D LAXO ATTORNEY ED LAXO v BUMPER STABILIZER FOR CAN BODY SIDE SEAMER Filed Feb. 18, 1960 2 Sheets-Sheet 2 nvmvrok ED LAXO BY ATTORNEY United States Patent 3,086,487 BUMPER STABILIZER FOR CAN BODY SIDE SEAMER i Ed Laxo, 27690 Orlando Ave., Hayward, Calif.

Filed Feb. 18, 1960, Ser. No. 9,468

3 Claims. (Cl. 11312) This invention relates to a can body side seamer employed to form side seams on can bodies.. More particularly it relates to a method of stabilizing andguiding the bumper employed for such purposes.

In can body makers the side seaming operation is performed by folding a can body blank about a forming mandrel or horn, interlocking hooks which have been preformed at the ends of the blank and then hammering the interlocked hooks to form the side seam.

These operations must be carried out at high speed and with a high degree of precision so that the side seams are formed rapidly and properly, e.g., Without deformation of the metal forming the side seams.

'One practice in this regardis to mount the bumper steel (which is the instrumentality which has actual impact with the interlocked hooks to form the side seam) on a slide. However, slides are disadvantageous because of difficulties in lubrication and because of their tendency to score and gall and the tendency of flux applied to the can body blanks to drip onto the slide 1 and foul it.

Rotary means of operating the bumper steelof a can body side seamer have been employed, more specifically in the form of a crank shaft, a connecting rod oscillated by the crankshaft and a cross head which is carried by the connecting rod and which supports the bumper steel. However, problems arise in connection with guiding the connecting rod and bumper steel.- More particularly rotary machines of this character tend to impart to the bumper steel a substantial horizontal component of motion at the instant of impact. This causes a shearing of the side seam, which is undesirable. It is desirable that the bumper steel have substantially no horizontal component of movement at the instant of impact,

It is an object of the present invention to provide improved means of guiding and stabilizing the connecting rod and the bumper steel carried thereby, of a can body side seamer in which rotary means such as acrankshaft is employed for operating the bumper'steel.

The above and 'otherobjects will be apparent from the ensuing description and the appended claims.

One form ofthe invention is shown by way of example in the accompanying drawings, in which:

FIGURE 1 isaview in end elevation of a can body side seamer employing a rotary operating means and a guide and stabilizing means in accordance with the present invention. x 1

FIGURE 2 is a view in side elevation as seen along the line 2-2 of FIGURE 1.

FIGURE 3 is a section taken along the line 33 of FIGURE 1.

FIGURE 4 is a view in end elevation, partly broken away, of the bumper steel of the machine of the present invention at the instant of impact and while flattening the interlocked hooks of a can body blank to form a side seam.

Referring now to the drawings, the machine is gnerally designated by the reference numeral and it comprises a frame 11 which supports, among other things, a forming horn or mandrel 12 of known construction and also an assembly generally designated by the reference numeral 13 Whose purpose is to clamp can body blanks to the horn 12 and to provide an anvil to take the impact of the bumper steel during side seam formation. Also shown is a can body blank 14 in position between the clamp assembly 13 and the forming horn or mandrel 12, such can body blank having oppositely folded hooks 15a and 15b which are interlocked to form the side seam. It will be understood that suitable means including wing clamps (not shown) are provided for folding the can body blank 14 about the horn 12 and interlocking the hooks 15aand 15b, such means being well known in the art and requiring no further description herein.

Referring to FIGURES l and 3, a connecting rod 17 is provided to which isattached a cross head 13 which in turn carries a bumper steel 19 which is bolted to the cross head at 20. The bumper steel 19' is detachable not only for the purpose of replacing a worn or broken bumper steel but also to substitute a bumper steel of diflerent length for can bodies of a different diameter.

Referring more particularly to FIGURE 3, the connecting rod :17 is rotatably mounted on a bushing 25 which in turn is mounted on the crankpin 26 of the crankshaft 27.

It is the rotary movement of the crankshaft 27 and the oscillatory movement imparted to the conecting rod 1'7 by means of the crankpin 26 that cause the connect: ing rod 17, and therefore the bumper steel 19 to reciprocate. It is necessary, however, to support the connecting rod 17 and to guide it during its reciprocating movement. The means whereby this is accomplished in. accordance with the present invention will now be described.

Referring more particularly to FIGURE 1 a pair of guide and stabilizer arms or levers 3t) and 31 are provided. As will be seen the arm 30 is rotatably connected to the frame at 32 on one side of the machine (to the left as viewed in FIGURE 1) and at its inner end the arm 30 is rotatably connected at 33 to a lever 34 whose upper end is fixed to the cross head 18 which in turn is rotatably mounted on a pin or shaft 35 which is carried by the upper end of the connecting rod 17. Caps 36 and bolts 37' secure the shaft 35 and cross head 18 to the connecting rod 17. p

The other guide arm or lever 31 is rotatably mounted on the frame at 38. It will be seen that the frame pivots 32 and 38 of the guide arms 30 and 31 are on opposite sides of the connected rod. As is best shown in FIG; URE 3; the other end of the guide arm 31 is rotatably mounted on the shaft 35. V

In operation can body blanks are supplied to the forming horn or mandrel 12 by suitable feed means (not shown). The clamping assembly 13 is operated to clamp each body blank 14 in position on the forming horn 12. Suitable wing clamps (not shown) operate to fold the can body blank 14 about the horn and to interlock the hooks 15a and 15b. The horn 12 is operatedby suitable expander. means (not shown) to expand the folded body blank and thereby tighten the interlocked hooks 15a and 15b. All of this is accomplished'by means which are well known in the art and which require no further description herein.

These operations are carried out in timed relation to rotation of the crankshaft 27. The latter causes the bumper steel 19 to elevate to the position shown in full lines in FIGURES 1 and 4, only after a can body blank 14 has been folded about the horn 12 and the hooks 15a and 15b are tightly interlocked as described. The impact of the bumper steel 19 against the interlocked hooks 15a and 15b causes a flattening of the hooks and brings about formation of a side seam as shown at 40 in FIGURE 4. Thereafter continued rotation of the crankshaft 27 causes retraction of the bumper steel 19, which will assume a position such as that shown in broken lines in FIGURE 1.

Upper guide arm 31, supported at 38, guides the axis of shaft 35 along a circular sector about 38. Suspension point 38 and arm 31 are respectively positioned and dirnensioned to form a right angle with connecting rod 17 when the latter is in its top position and striking seam 40. Therefore the circular sector described by the axis of shaft 35 is tangential to the center line of rod 17 when striking seam 40 and there is no horizontal component of motion. However during the approach to the striking position, center of shaft 35 moves vertically and slightly to the left as viewed in FIGURE 1.

Bumper steel 19 is angularly positioned by extension arm 34 and guide arm 30 about the center of shaft 35. Arms 34 and 30 are dimensioned and pivoted so that their combination angularly positions bumper steel 19 to be straight up when connecting rod 17 is in its upmost (striking) position. Upon approaching the striking position, point 33 will move along a circular sector about 32 which is also tangential to the center line of connecting rod 17 in its striking position. Accordingly point 33, during approach to the striking position moves upwards and slightly to the right as viewed in FIGURE 1.

Bumper steel 19, being rigidly connected to arm 34, will describe exactly the same motion as arm 34. The motion of arm 34 is the motion of a bar whose ends are fixed to two points which move along circular sectors curving in opposite directions. Such a motion is partly translational and partly rotational. In other words, bumper steel 19 rotates about the center of shaft 35 and translates along an arcuate path about 38. At the point of impact, the end points of arm 34 have only a vertical component of motion because the circular sectors along which the end points move are tangential to the center line of connecting rod 17 and consequently bumper steel 35 moves only in a vertical direction. It has been found that such a compounded motion, i.e., a motion which is partly rotational and partly translational, produces a superior seam on the cans and places a minimum of wear upon the bumper steel 35.

Moreover it will be apparent that, at the moment of impact, the two arms 30 and 31 are horizontal. This has the advantageous result that at the moment of impact, which is the moment when the greatest strain is placed on the machine, the load and shock are divided equally by the two arms 30 and 31.

It will, therefore, be apparent that a can body side seamer has been provided which has novel and advantageous features. More particularly, a means is provided for guiding the bumper steel so that, at the critical moment of impact when the maximum forces are imposed on the moving parts and when the direction of movement of the bumper steel is critical in relation to the quality of the side seam, the bumper steel has an almost completely vertical movement with substantially no horizontal component.

I claim:

1. A can body side seam forming machine comprising:

a stationary frame,

a horn for supporting a can body blank having folded edges with the blank wrapped about the horn and the folded edges of the blank interlocked,

a bumper member for bumping said interlocked, folded edges to flatten the same and form a side seam,

means for reciprocating said bumper member to accomplish such side seam forming operation, said means comprising a rotary eccentric member,

a connecting rod rotatably carried at one end by said eccentric,

and a cross head pivotally mounted on the other end of said connecting rod, said bumper member being fixed to said cross head;

and stabilizer and guide means for said connecting rod and cross head in the form of a first guide arm pivotally connected at one end to said frame on one side of the connecting rod and a second guide arm pivotally connected to the frame on the opposite side of said connecting rod,

said first guide arm being rotatably connected at its other end to said connecting rod coaxially with said cross head,

said second guide arm being rotatably connected at its other end to a portion rigid with said cross head and displaced from the pivotal axis thereof,

the arrangement of said guide arms and connecting rod being such that the connecting rod is held in upright position at all times and, at the instant of impact of said bumper member with said interlocked folded edges the bumper member is substantially perpendicular to the plane of the side seam and is travelling substantially perpendicularly thereto.

2. The can body maker of claim 1 wherein said cross head has an extension to which said second guide member is rotatably connected.

3. The can body making machine of claim 2 wherein said cross head extension extends downwardly from the cross head and to that side of the connecting rod on which the first guide arm is pivoted, and said second guide arm is rotatably connected to said extension on said side.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Product Engineering, Oct. 12, 1959, issue, page 86. Figure 2 relied on. 

1. A CAN BODY SIDE SEAM FORMING MACHINE COMPRISING: A STATIONARY FRAME, A HORN FOR SUPPORTING A CAN BODY BLANK HAVING FOLDED EDGES WITH THE BLANK WRAPPED ABOUT THE HORN AND THE FOLDED EDGES OF THE BLANK INTERLOCKED, A BUMPER MEMBER FOR BUMPING SAID INTERLOCKED, FOLDED EDGES TO FLATTEN THE SAME AND FORM A SIDE SEAM, MEANS FOR RECIPROCATING SAID BUMPER MEMBER TO ACCOMPLISH SUCH SIDE SEAM FORMING OPERATION, SAID MEANS COMPRISING A ROTARY ECCENTRIC MEMBER, A CONNECTING ROD ROTATABLY CARRIED AT ONE END BY SAID ECCENTRIC, AND A CROSS HEAD PIVOTALLY MOUNTED ON THE OTHER END OF SAID CONNECTING ROD, SAID BUMPER MEMBER BEING FIXED TO SAID CROSS HEAD; AND STABILIZER AND GUIDE MEANS FOR SAID CONNECTING ROD AND CROSS HEAD IN THE FORM OF 